Character customization in SWTOR is also made possible through a concept called advanced classes. It is a specialization of your primary class into one of two paths.

Today at GamesCom 2010 the working titles of all 16 advanced classes were revealed. They are:

Smuggler

Scoundrel (Stealth/Medicine; Burst ranged damage or healing)

Gunslinger (Dual pistols, Quick draw, Ranged DPS)

Sith Inquisitor

Sorcerer (Single saber; ranged damage class; Healing; Think of someone that just loves using lightning; Think Palpatine; They even heal with lighning (joke, but they do heal))

Assassin (Double bladed light sabers, a lot of melee damage, When you think about the Assassin think about Darth Maul and Zabrak and tattoos. That’s the general vibe they are going for)

Jedi Knight

Sentinel (dual saber (not double), melee DPS; Think young Anakin)

Guardian (tank, party buffs, Think Obi Wan leading the attack with the troops

Trooper

Commando (ranged tank)

Vanguard

Imperial Agent

Operative (blaster rifle, burst ranged damage, stealth)

Sniper (dps)

Bounty Hunter

Powertech

Mercenary

Jedi Consular

Shadow (double-bladed lightsaber)

Wizard (healing; single lightsaber)

During our talk with James Ohlen, he said that they wanted to have 4 healing capable classes so that out of 16 available advanced classes, 25% can heal and when you translate that to a group of 4 there will always be one class capable of doing some heals. (If they spec for healing option of course)